通心络抑制KK/Upj-Ay小鼠视网膜组织HIF-1a/VEGF/VEGFR-2表达

目的:观察通心络对自发糖尿病KK/Upj-Ay小鼠视网膜组织缺氧诱导因子-1a(HIF-1a),血管内皮生长因子(VEGF)和血管内皮生长因子受体2(VEGFR2)基因及蛋白表达的影响,探讨通心络对糖尿病视网膜病变的保护机制。方法:40只KK/Upj-Ay小鼠随机分为模型组和通心络低、中、高剂量组(通心络生药1,2,4 g·kg-1,ig给药12周),实验以C57BL/6小鼠为正常组。用血液黏度仪测定全血黏度和血浆黏度、红细胞变形聚集仪测定红细胞聚集指数;应用实时荧光定量PCR法检测各组小鼠视网膜组织中VEGF和VEGFR2的基因表达;Western blot法检测视网膜组织中HIF-1a,VEGF,VEGFR2蛋白的表达。结果:与正常组C57BL/6小鼠比较,模型组小鼠全血黏度、血浆黏度、红细胞聚集指数明显升高(P0.01);与模型组比较,应用通心络中、高剂量治疗的KK/Upj-Ay小鼠红细胞聚集指数明显降低(P0.05,P0.01);高剂量通心络组的低切全血黏度降低(P0.05),血浆黏度较模型组也显著降低(P0.01)。模型组小鼠视网膜组织HIF-1a,VEGF,VEGFR2蛋白和VEGF,VEGFR2 mRNA表达较正常组明显增高(P0.01);通心络ig治疗后,各剂量组HIF-1a,VEGF,VEGFR2 mRNA和蛋白表达水平均较模型组明显下降(P0.01)。结论:通心络可抑制自发性糖尿病小鼠视网膜组织HIF-1a/VEGF/VEGFR-2信号途径,此作用可能与其改善糖尿病血液流变学相关。

Tongxinluo Inhibits Expression of HIF-1a/VEGF/VEGFR-2 Expression in Retina Tissues of KK/Upj-Ay Mice

Objective: To observe the effect of Tongxinluo on expression of hypoxia inducible factor 1a (HIF-1a), vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor 2 (VEGFR2) in retina tissues of KK/Upj-Ay mice with spontaneous diabetes, and explore the protective mechanism of Tongxinluo on diabetic retinopathy. Method: Forty KK/Upj-Ay mice were randomly divided into 4 groups:model group (n=10), Tongxinluo low-dose group (n=10, 1 g·kg^-1), median-dose group (n=10, 2 g·kg^-1) and high-dose group (n=10, 4 g·kg^-1) group. The mice were given Tongxinluo intragastrically for 12 weeks. C57BL/6 mice were chosen as normal group (n=10). The whole blood viscosity and plasma viscosity were measured by blood viscometer and red blood cell aggregation index was measured by ektacytometer. The expression levels of VEGF and VEGFR-2 genes in retina tissues of mice were detected with real time fluorescence quantitative PCR method. Western-blot method was used to detect the expression levels of HIF-1a, VEGF, VEGFR2 in retina tissues. Result: Compared with C57BL/6 mice in the normal group, the whole blood viscosity, the plasma viscosity and the red blood cell aggregation index were all increased in model group (P<0.01). Compared with the model group, red blood cell aggregation index was significantly decreased in KK/Upj-Ay mice after treatment by middle dose and high dose Tongxinluo (P<0.05,P<0.01), and the whole blood viscosity at low shear rate, and plasma viscosity were also significantly decreased in high-dose Tongxinluo group (P<0.01). HIF-1a/VEGF/VEGFR-2 proteins and VEGF/VEGFR-2 mRNA expressions in retina tissues of model group mice were significantly higher than those in normal group (P<0.01), while after treatment with Tongxinluo, HIF-1a/VEGF/VEGFR-2 mRNA and protein expressions were significantly lower in low-dose, median-dose and high-dose groups than those in model group(P<0.01). Conclusion: Tongxinluo may inhibit HIF-1a/VEGF/VEGFR-2 signal pathways in retina tissues of diabetic mice, which may be related to it's improvement of hemorrheology.